1. Field of the Invention
The present invention relates to a resin film, a production method thereof, a polarizing plate using the resin film, and a liquid crystal display device.
2. Description of the Related Art
The usage of a liquid crystal display device is being broadened year by year as a space-saving image display device with low power consumption. Conventionally, the large viewing angle dependency of image is a great defect of the liquid crystal display device. However, in recent years, a liquid crystal mode assured of high viewing angle by a VA mode is put into practical use and by virtue of this mode, the demand for a liquid crystal display device is abruptly expanding also on the market requiring a high-quality image, such as television.
The VA-mode liquid crystal display device is advantageous in that the contrast is generally high as compared with other liquid crystal display modes, but there is a problem that the contrast and tint are greatly changed depending on the viewing angle. For solving this problem, a method of using two kinds of retardation layers differing in the optical properties and thereby obtaining a VA-mode liquid crystal display device where the black display is clear and achromatic even when viewed from an oblique direction, is disclosed (see, for example, JP-A-2003-121641 and JP-A-2006-323329 (the term “JP-A” as used herein means an “unexamined published Japanese patent application”)).
Furthermore, in International Publication No. 2003/032060 pamphlet, a method of improving a tint change depending on the viewing angle by combining an A plate with Re becoming smaller on the shorter wavelength side and a C plate with Rth becoming larger on the shorter wavelength side is proposed.
Particularly, as for the A plate of which Re becomes smaller on the shorter wavelength side, in addition to the stretched film of modified polycarbonate described in International Publication No. 2003/032060 pamphlet, for example, a stretched cellulose acylate film is proposed in JP-A-2002-22941 and a stretched film of modified norbornene resin is proposed in JP-A-2003-292639.